After you file

Thanks to Vanessa, original answer posted here.

Generally, a U.S. citizen or resident alien who is married to a nonresident alien uses the married filing separately filing status.  This is probably the simplest but may not result in the best tax benefits.

You do have 3 possible options

1. You can make an election to file a joint return (she will need an ITIN)or;
2. File as Head of Household IF you are maintaining a home for certain dependents or relatives other than your wife
3. Married Filing Separately (if your spouse does not have an ITIN you will need to paper file your return and write NRA in the space for your spouses SSN)

To make the Election to File a Joint Return:

• You and your spouse are treated, for federal income tax purposes, as residents for all tax years that the choice is in effect. However, for Social Security and Medicare tax withholding purposes, the nonresident alien may still be treated as a nonresident alien.
• You must file a joint income tax return for the year you make the choice (but you and your spouse can file joint or separate returns in later years).
• Each spouse must report his or her entire worldwide income for the year you make the choice and for all later years unless the choice is ended or suspended.
• Generally, neither you nor your spouse can claim tax treaty benefits as a resident of a foreign country for a tax year for which the choice is in effect.

https://www.irs.gov/individuals/international-taxpayers/nonresident-alien-spouse

Filing As Head of Household Qualifications

Although your nonresident alien spouse cannot qualify you as a head of household, you can qualify if (1) or (2) applies:

1. You paid more than half the cost of keeping up a home that was the principal home for the whole year for your mother or father for whom you can claim an exemption (your parent does not have to have lived with you), or
2. You paid more than half the cost of keeping up the home in which you lived and in which one of the following also lived for more than half the year:

• Your unmarried child, grandchild, stepchild, foster child, or adopted child. A foster child will qualify you for this status only if you can claim an exemption for the child
• Your married child, grandchild, stepchild, or adopted child for whom you can claim an exemption, or for whom you could claim an exemption except that you signed a statement allowing the noncustodial parent to claim the exemption or the noncustodial parent provides at least $600 support and claims the exemption under a pre-1985 agreement
• Any relative listed below for whom you can claim an exemption: (please click on link to see list of relatives)

https://www.irs.gov/individuals/international-taxpayers/us-citizens-and-resident-aliens-abroad-head-...

Married Filing Separate

You may (BUT DO NOT HAVE TO) still be able to claim an exemption for your spouse if the following apply:

• ·        Must have no gross income for U.S. tax purposes,
• ·        Must not be filing a return,
• ·        Must not be the dependent of another taxpayer.
• ·        Has an ITIN

https://www.irs.gov/pub/irs-pdf/p17.pdf  (page 25-26)

Nonresident alien or dual-status alien. Generally, a married couple can’t file a joint return if either one is a nonresident alien at any time during the tax year. However, if one spouse was a nonresident alien or dual-status alien who was married to a U.S. citizen or resident alien at the end of the year, the spouses can choose to file a joint return. If you do file a joint return, you and your spouse are both treated as U.S. residents for the entire tax year. See chapter 1 of Pub. 519, U.S. Tax Guide for Aliens.

For instructions on applying for an ITIN, click here https://www.irs.gov/individuals/how-do-i-apply-for-an-itin

@zidanea